Fair Value - Information About Our Fixed Rate Financial Instruments Not Measured at Fair Value (Detail) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013		Dec. 31, 2012
Carrying Amount [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Loan secured by real estate	$ 16,713		$ 18,507
Fixed rate debt	(103,008)	[1]	(3,989)	[1]
Fair Value [Member] | Level 2 [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Loan secured by real estate	30,968		35,824
Fixed rate debt	$ (91,235)	[1]	$ (4,070)	[1]

[1] Second quarter-end 2013 includes our 3.75% convertible senior notes due 2020, issued February 26, 2013.